class Solution {
    public int[] twoSum(int[] nums, int target) {
        Map<Integer,Integer> map = new HashMap<>();
        
        for (int i = 0; i < nums.length; i++) {
            if (map.containsKey(target - nums[i])) {
                return new int[] {i,map.get(target-nums[i])};
            }
            map.put(nums[i],i);
        }
        return new int[0];
    }
}